Rapid and Selective Cleavage of Amide Groups at Neutral pH: Applications from Hyaluronic Acid to Small Molecules

2018 ◽  
Vol 2018 (23) ◽  
pp. 2995-3000 ◽  
Author(s):  
Jing Jing ◽  
Johan Bankefors ◽  
Céline Bonneaud ◽  
Elin Sawen ◽  
Thibaud Gerfaud ◽  
...  
2018 ◽  
Author(s):  
Martin A. Fascione ◽  
Richard J. Spears ◽  
Robin L. Brabham ◽  
Darshita Budhadev ◽  
Tessa Keenan ◽  
...  

The bioconjugation of proteins with small molecules has proved an invaluable strategy for probing and perturbing dynamic biological mechanisms. The general use of chemical methods for the functionalisation of proteins remains limited however by the frequent requirement for complicated reaction partners to be present in large excess, and harsh reaction conditions which are incompatible with many protein scaffolds. Herein we describe a site-selective organocatalyst-mediated protein aldol ligation (OPAL) that affords stable carbon-carbon linked bioconjugates at neutral pH under biocompatible conditions. OPAL enables rapid chemical modification of proteins within an hour using simple aldehyde probes in minimal excess, and is utilised here in the selective affinity tagging of proteins in cell lysate. Furthermore we demonstrate that the b-hydroxy aldehyde product of the OPAL can be functionalised a second time at neutral pH in a subsequent organocatalyst-mediated oxime ligation. This tandem strategy is showcased in the ‘chemical mimicry’ of a previously inaccessible natural dual post-translationally modified protein integral to the pathogenesis of the neglected tropical disease Leishmaniasis. <br>


2016 ◽  
Vol 52 (74) ◽  
pp. 11151-11154 ◽  
Author(s):  
Liyang Shi ◽  
Yuanyuan Han ◽  
Jöns Hilborn ◽  
Dmitri Ossipov

A new self-healing hydrogel is developed using dynamic coordinate bonds between drug loaded MgSiO3 nanoparticles and bisphosphonate functionalized hyaluronic acid. The nanocomposite network is stable at neutral pH, but is disassembled in an acidic environment, providing “smart” drug release.


2020 ◽  
Vol 8 (32) ◽  
pp. 7275-7287
Author(s):  
Parinaz Sabourian ◽  
Jeff Ji ◽  
Victor Lotocki ◽  
Alexandre Moquin ◽  
Ramez Hanna ◽  
...  

Chitosan is functionalized with oxidative stress-sensitive thioketal entities in a one-pot methodology, and self-assembled into drugs or protein loaded dual stimuli responsive nanoparticles, which kill glioblastoma cells and increase nerve outgrowth.


2018 ◽  
Author(s):  
Martin A. Fascione ◽  
Richard J. Spears ◽  
Robin L. Brabham ◽  
Darshita Budhadev ◽  
Tessa Keenan ◽  
...  

The bioconjugation of proteins with small molecules has proved an invaluable strategy for probing and perturbing dynamic biological mechanisms. The general use of chemical methods for the functionalisation of proteins remains limited however by the frequent requirement for complicated reaction partners to be present in large excess, and harsh reaction conditions which are incompatible with many protein scaffolds. Herein we describe a site-selective organocatalyst-mediated protein aldol ligation (OPAL) that affords stable carbon-carbon linked bioconjugates at neutral pH under biocompatible conditions. OPAL enables rapid chemical modification of proteins within an hour using simple aldehyde probes in minimal excess, and is utilised here in the selective affinity tagging of proteins in cell lysate. Furthermore we demonstrate that the b-hydroxy aldehyde product of the OPAL can be functionalised a second time at neutral pH in a subsequent organocatalyst-mediated oxime ligation. This tandem strategy is showcased in the ‘chemical mimicry’ of a previously inaccessible natural dual post-translationally modified protein integral to the pathogenesis of the neglected tropical disease Leishmaniasis. <br>


Polymer Korea ◽  
2021 ◽  
Vol 45 (4) ◽  
pp. 601-609
Author(s):  
Yu Rim Je ◽  
So Ra Bang ◽  
Il Keun Kwon ◽  
Sang Jun Park ◽  
Chun-Ho Kim
Keyword(s):  

2015 ◽  
Vol 3 (40) ◽  
pp. 8010-8019 ◽  
Author(s):  
Joshua E. Mealy ◽  
Christopher B. Rodell ◽  
Jason A. Burdick

Shear-thinning hyaluronic acid hydrogels based on modifications of β-cyclodextrin and adamantane were developed for the tunable, sustained release of small molecules, through regulation of cyclodextrin content and affinity for cyclodextrin.


2020 ◽  
Vol 8 (31) ◽  
pp. 15681-15686
Author(s):  
Sean Clair ◽  
Michael R. Norris

Immobilization of electroactive molecules without synthetic modification that are stable at neutral pH!


2005 ◽  
Vol 127 (1) ◽  
pp. 325-330 ◽  
Author(s):  
Kristian M. Roth ◽  
Yan Zhou ◽  
Wenjun Yang ◽  
Daniel E. Morse

Author(s):  
J. P. Robinson ◽  
P. G. Lenhert

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.


Author(s):  
Ji-da Dai ◽  
M. Joseph Costello ◽  
Lawrence I. Gilbert

Insect molting and metamorphosis are elicited by a class of polyhydroxylated steroids, ecdysteroids, that originate in the prothoracic glands (PGs). Prothoracicotropic hormone stimulation of steroidogenesis by the PGs at the cellular level involves both calcium and cAMP. Cell-to-cell communication mediated by gap junctions may play a key role in regulating signal transduction by controlling the transmission of small molecules and ions between adjacent cells. This is the first report of gap junctions in the PGs, the evidence obtained by means of SEM, thin sections and freeze-fracture replicas.


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